1. Text Book of Ophthalmology. p. 741. 1917.
2. Diseases of the Eyes. 8th Edition, p. 456.
3. Diagnosis From Ocular Symptoms. p. 354. 1917.
4. Graefe-Saemisch-Hess, v., vii., p. 28. (Medical Ophthalmology, Knapp, p. 370).
5. Text Book of Ophthalmology.